The backstamp has been dated to 1930+, and I think the plate is probably no older than the 1930s - I'm not sure I've seen that shape used in later decades, but I am no expert.
This is the backstamp giving the date as 1930+. The registered number of 788985 seems to be the number for the Fruitful Tree pattern.
I acquired this from an antique shop in Ascot Vale around 30 years ago.
